Re: [PATCH 3/4] sched/numa: Apply imbalance limitations consistently

Peter Zijlstra
2022-05-18T13:59:53Z

On Wed, May 18, 2022 at 11:46:52AM +0100, Mel Gorman wrote:

> > (Although I do wonder about that 25% figure in the comment; that doesn't
> > seem to relate to any actual code anymore)
> >
>
> You're right, by the end of the series it's completely inaccurate and
> currently it's not accurate if there are multiple LLCs per node. I
> adjusted the wording to "Allow a NUMA imbalance if busy CPUs is less
> than the maximum threshold. Above this threshold, individual tasks may
> be contending for both memory bandwidth and any shared HT resources."
>

Looks good. Meanwhile I saw a 0-day complaint that this regresses
something something unixbench by a bit. Do we care enough? I suppose
this is one of those trade-off patches again, win some, loose some.